Mega political donor Dick Uihlein has made his choice in the GOP primary race for Illinois governor, shifting his allegiance - and his funding - to support the more conservative candidate.

In doing so, Uihlein, who was already widely considered one of the most influential Republican fundraisers in Illinois, has become an even more prominent figure, as state Rep. Jeanne Ives' backer with the deepest pockets.

Uihlein donated $2 million to Ives' campaign to unseat incumbent GOP Gov. Bruce Rauner, her campaign announced Sunday. Just the week before, he sent her an initial contribution of $500,000.

Those donations are key to keeping Ives' campaign alive against Rauner - a former private equity investor who dumped $50 million into his own war chest in December 2016.

It also marks a major shift in support. Uihlein has contributed $2.6 million to Rauner in the past, but has not given him anything since 2014, the year he was elected.

Uihlein has also given $3 million to Liberty Principles PAC, run by Dan Proft, who also once supported Rauner - but no longer.

Uihlein and his wife Liz own Uline Corporation, a shipping and office supply company that distributes 30,000 products, ranging from bags to bubble wrap to barcode labels. The couple lives in Lake Forest and Wisconsin, often sharing their conservative political views with customers and employees alike.